Brake tester



Nov. 23 1926.

-.1. J. GRABFlLD er AL JUHN J. GRHFSFIELD` FREDERLCK H. KINEH IR.

- BRAKE TESTER Filed August 6. 1923 2 i 4. v rmlr, ZIE

'i .Patented Nov. z3,h 192e.

and easily applied to s, I. Afiiggjll is asectionlongitudinalljv itlirouglifil the device, th

"fthe present .invention is to outin'the'felai'ms ':Thej drawings illustrate both in section.

device.

u-Ni'r D STATES PAT EN 'JO'HN'J; (inhumana-or nmen'romnassiionnsnmrs, ,ennrnnnnnzo'x A. man, m., i

.v l orwiisrrmrnn, New

JERSEY.l

Ammann4 ma August e, i923. serieu. mi'. 655,952;

ble members one member `capable of being connected to the revolving element and havj ing movement therewith, and 4the .other mem'- ber' being rotatable independent of the re-l volving element but having means connected thereto Which gradually retards and finally stops'the movement of said member.

One of the objects of the invention is to provide .such a device of novel design which may be vapplied to the end of a revolving r element asa shaft` and measure the rate of decreasein speed of rotation 'A further object of the provide. suoli a device which is simple in operation and construction and which is compact so that it may be easily supported a revolving element. Another objecto'fjthe present invention is to provide such a device which may be apof the element.

.pl-ed to anyV revolving element within the limits of thedevice.

A further and more particularobject of rovide such a devicenwhich maybe apple to the hub of a-nautomobile Wheel to measure the rate at whichEth-e wheel is .stopped or slowed down when the'brakes are applied and thus measb ureptheeiciency of the brakes.

Other Aobjects and features of the invenore Afully appear .from Ath following' ves'cription and theaccompanyin drawings-fand will be particularly. pointedand elevation'fa preferred 'form ofi construe. j ltionfof the .device and .embody the broad e' 0f memberbeing shown in side elevation an the "ratchets'ldand 11 beingshown broken cou ling omitted;

.dial,and -the. 'inter' Eig., 4 `is a' detail o i' 'r11-emechanism 'illustrated' is. design be' used n'ennection' -rotation ofsuch element.A The d which is decreasing` such' speed.

mobiles in' which automobile are lifted from the ground and invention is to l were incontact or 'other ,placey vvithoutbeingtaken;

f the w e indicatino placed is a vfront elevation ofthe indicia-v .onthesha me n.. the speedfindicatiiig may have niovementg-relativet :one another.' f

" One of them'embe ed to fixedmfthef sha-ft and the other ith any -rotatingfele.-

Qn vgi--iffshaft: so that it; mayfliavemovementj.

ment rvvhich' may operate -at various speeds determine the rate o fchange inthe speed of evice in its present ,embodiment is'lparticularly designed to' be placed against thegendof a revolving shaft which isdecreasing its s eed of rota' tion to determine the rate. o decrease'of speed, and, thus determine the either the. Vmeans -which is increasing the speed ofI rotation of the element'o the meansy t is cuiA

articula'rlyuseful in testing the brakes o \autocase vthe rear wheels of the then rotated by any means such 4as connecting the wheels with the motor of theautomo' bile .and after the' Wheels havey reached a certain speed corresponding'with a certain number of miles pervhour at which the auto mobileA would be. travelling if the wheels* force b brakes'- are suddenly lappliedto the wheels with 4the ground, the Wheels'l are.suddenlydi'sconneeted from the drivin and the brakes the instrument registersl the speed with the brakes s to'p the revolution of the wheels. In this'way A the brakes of automoiles may be convenientlytested iny a garage on the road for a road test Onejof the featuresof the inventionis 'the particular formfofV Y'eoupliiig 'by 'means of I "which-'the"instrumentfmay be coupled to the 'The coupling 1s -in the formlof-ftlie -rf'ustrum'of a cone, vthe base )of the frustruni being; thatfpart of 'the 1f.' coupling which isv outside.. `Wh

en itis' imendof eel 'in .be cested,,-th against the .95: possible'to connect! the Ainstrument l.witlv the a vrevolving shaftonwith the hub 'of V Cvupling'may be' lfy'o thefrevolvmg 'lementanda meister any change sin' 11,00

speed offretati'oninY theelementas though it manner. j 'u rably rigidly 'V 'is` mounted llo independent thereof. s shown in the drawings the indicia-carrying` member 1s 1n the form of a disk having thereon the indices 4 and is fixed to the shaft by means of a key 5. The indicating member is preferably in the form of a pointer loosely embracing the shaft for free rotation thereon but connected to the shaft by some means, such as a spring 6 in such manner that lthe pointer may have movement past the disk. In the preferred form of the construction a sleeve 7 is fastened -to the shaft for rotary movement therewith and the indicating member is loosely mounted on the sleeve while the spring is fastened at the outer end to the pointer and at the inner end to the sleeve. The spring may conveniently be connected to the pointer by means of an arm 8 which projects from the pointer and to which, the outer end of the spring is fastened. A^ counterweight 9 is provided on the end of the indicating member in order to counterbalance the weight of the indicating member and attached parts.

In order to retain the indicating member and the indicia-carrying member in their positions of farthestrelative movement a pair of ratchets 10 and 11 having opposed teeth are fastened to the shaft by means of the key 5 and to the disk by means of screws 12. The ratchets co-operate with a pair of pawls 13 and 14 carried on an arm 1 5, which may conveniently be a continuation of the arm 8, in such a manner that either pawl may be made to engage with the appropriate ratchet. To this end the ratchets 10 and 11 are spaced apart by a washer 16 andthe pawls 13 and 14 are held in the space be-v tween the ratchets. A spring 17 fastened to the arm 15 engages the pawls to yieldingly retain them in engagement with the teeth of the ratchets when said pawls are moved into operative position. By the use of two pawls and ratchets operating in opposltedirections the device may be used in conjunction with elements which are revolving in either direction by causing either one or the other of the pawls to engage with its ratchet. I

To move the pawls into operative position the sleeve 7 is splined to the shaft for movement longitudinally thereof so that when the sleeve is moved in one direction along the shaft the pawl 13 may be madeto engage with the ratchet 10 and when lthe sleeve is moved in the other direction along the shaft the pawl 14 may be made to engage with the ratchet 11. The sleeve may be moved in any suitable manner as by a lever 18 fulcrumed at 19 to a stationary support 20 with one end projecting to the outside of the instrument and the other end fastened b v a Vsliding ronnection 21 to a collar 22 which surrounds the sleeve in such a man-- ner that the sleeve'may revolvewithin it.

recaen' rThus by lmoving the outer end of the lever 18, the collar 22 and indicating member 3 are moved to cause either pawl to engage with the appropriate ratchet.

in orderto retain the indicating member and the collar 22 -on the sleeve and transmit motion from the iollar to the indicating member rings 23 and 24 or other suitable means are removably fastened on the ends of the sleeve which is preterably formed witha shoulder 25. This shoulder separates the indicating member and the collar and thespring 6 may conveniently' be fastened to the sleeve by being secured to the shoulder 25, thus freely operating in the space between the indicating member and the collar 22.

It willbe seein that when .the shaft 1 is rotated, the disk 2 is moved with the shaft and the indicating member is also carried with the shaft due to the engagement of the pav'vl carried by the indicating member. with the rat het carried by the shaft. When the shaft stops the indicia-carrying member stops at the same instant but the indieating member continuesits rotary movement until it is finally brought to rest by the tension of the spring which connects said member to the shaft, the pawl meanwhile slipping over the teeth of the ratchet until the indicating member comes to rest. At this time the pawl engages with the nearest tooth on the ratchet to hold the indi- 'eating member in the position at which it comes to rest. Thus if theshaft beI connected to a revolving element which suddenly stops, the shaft anddisk also suddenly stop but the indicating lmember continues its rotary movement until the spring brings 1t to rest.

The distance to which the indicating member will moverelative-to the disk depends upon the speed with which theishaft i was revolving and its rate of change of speed when coming to rest and, also `upon thecharacteristics of the spring. Since in a given instrument the characteristics of the lll) spring are constant, the distance to which the indicating member will move past the dlsk is determined by the speed` of rotation of the shaft disk 'and indicating member -and the quickness withvwhich the rotation l of the disk and shaft are stopped.` There fore, if the, second condition, namely the speed of rotation prior to any change in speedyis the same during a series oftests with the instrument and the rate of change of the speed of rotation is varied, the ihdicating member will move past the indiciacarrying member a distance depending upon the rate at which the speed of rotation is changed. Thus if the instrument is applied to the end of a shaft which is rotating at a certain speed and the shaft is suddenly stopped, the indicia-carrying member will first test. If brakes'are used'tochange the The front of the casing is provided 'Awitlil k' `1 5 7 ,71 v move ypast 'thejdisk tolta point depending. whichy the end of the lever 18 projectsl and l 'l u pon t erate of change of speed Ao'f,i'ota` also with a. slot 42 through which `projects r tion. If the shaft` is again brought to the the arm 32. The pivot 33 mayconveniently saine speed and is stopped, but not quite ias be a screw which is screwed into the casing pointer willnot move 'quite as far past the .also'serve asa'means to hold the support disk as in the first test,'and will register a 20.v and to that end the support 'is provided rate: of change 1n speed of rotationv Which with a flange 43 which is held 'against the will be. less than the rate vof change in the casing by screws 44.

.ofrotation the-distancewhich the in transparent'material 45 in order that the di'cating member moves past the'disk'isftl'ien 4rela-tive positions j of' the indicia-carrying" Y i a measure of therate atjwhich the brakes member and theindicating'iriembermayV be stop the rotation of the shaftand is thus a (observed. Such transparent material may be measure of the eiciency of the brakes. u glass or celluloid but is preferably a sub# 804 In order to determine the, speed of rotal. stante which will not easily be broken. durtion of therevolviiig element to beltested ingthe rough usage to .which the tester will tion Iwith the Vtester and is actuated by 0n`e' mayfbe removably retained in place `by a a speed indicator is provided ingcon-junc ber subjected.y The transparent material- 4" suddenly as 'it was inl the firsty test, the to retain the belltliereon. The casing may I0A Y of .themoving lparts ofthe tester.` Such ring'46 of such a size that it over-lies the` 8a vspeed indicator is preferably .a ball 26y car-A edge of the material and is fastened -to theV ried on an arm 27 which ispivoted at 28 to edge of the casing by spaced screws y4 7 after" a second arm 29 fastened to the shaft 1 and the material has been putin place. Handles a bell 30 against which the ballmay strike.. 48 are preferablyV fastenedto the periphery'- I 5 Thus when the shaft is revolving the centrifof the casing for the, convenient holding of 9eI I I l uga'l force -throws ithe'ball 26; outwardly the tester when it is used. Directions for and enlarges the radius of'the circle t'liroughy the use of the instrument may be stamped on whichl the ball moves. The faster the-.shaft the casing near the slots 41' and 42.. to inrevolves the greater will be the'radius fof dicate theuses of the lever 18 and arm 32 '.30 the circle. Thebell 30 is held ,in such a and knobs' 49 may be fastened on the ends position that it may be moved into and out of the lever and arm for the convenience 4ofthe pathI of the ball 26 so that'every time Lof ,the operator. e the shaftrotates the ba11-will ring the bell, f A novel form of coupling has been used provided the shaft is rotating at such a in order to couple the indicator withv rotatv 3" speed that the centrifugal force will throw ingelements of various sizes. The coupling 100 the hall OlltWIdlY .IIO Such HPOSOQ that comprises a member 50 shaped like the frusit hits the bell. vThus the position to which trum of the cone with a portion of greatest the bell must be'moved before it is struck b v diameter extending outwardly and a porthe revolving ballwi-ll-indicate the speed 0f tion, of smallest diameter joining anaperrevolution lof the shaft and the slower the tur-ed sleever 51 which projects vtherefrom ips speed-of revolution the nearer the bell' will y'toreceive the end of the shaft -in any suitliave tobe tothe center of the shaft 1 before -able manner as by' a' screw 52 ythreaded I i` theball will .strike thegbell. The bell may. through an opening inthe sleeveand en-l ;0 :the shaft '1; The .distance to which the .b'allr shaft. It will be seen that with this coupling' a be supported iff/any suitable'. manner.' As gagingthe shaft.-

5 shown herein tliewbell is held'ona post 31 The member 50 is faced with a material 11o:YY

l Which extends from an arm 32# The arm is 53 such as rubber which will firmly engage pivoted at 3,3inwsuch a positionthatfmovewithout slippingthe end of.) a revolving 4ment of the arm' will bring the bell 'either shaft or other element and drive thetesting closer to orfarther'awayfrom'the center of device at the same speedas the revolving will be, thrown. maybe 4governed by placing any shaft having a diameter lbetween the a suitablespring .34 between-the rar'ms- 27 large andthe small diameters of the frusand 29.' 'tram of thelcone may be connected, .lo the We havelierein hown the devicefascomtesting vdevice and when the coupling yis prising a second bill 35 onan armI 36 which ,l placed against the end of the revolvingv eleien.

is also pivoted at the point 28 fand controlled ment said coupling will automatically be by a'sp'iingy 37.- -The'arm 29 may be fastened centered on the revolving element.

tothe shaftjin'any-suitable mannerland as In vcase the device cannot conveniently `shown on th'e drawings saidarm 29fisfasbe' applied to tlie end ofthe revolving elen tenedl to a collar "38 "which in turn is ment the member 50 is provided with a hori- 125 u .fa-Sfe'nedvto thes'haftby merSlIlS-Qfhe' key5- vzontalportion .54 which is coveredfwitlr. a I VThe mechanism of the 1 tester is `"e'i'iclosed friction material .55 so'that when the device in* a casing 39-lfia'ving"aprojectingl boss 40 is held 'against the peripheryof arevolving which forms a bearing for. the-shaft 1. The element, the material will frictionally eni" aSin'g; is` provided .witlrl a 'slot l4 1 through gage with 4the element land drive the tester uw bearing plate '56 may be placed between the pins 57, and

portion and the end of the sleeve 51 in order to take the thrust of the coupling against the casing.

The various parts and units of the device may be held in their relative positions on the shaft by any suitable means suoli as cotter the indicia-carrying disk 2 may be provided with a slot 58 to permit it to move past the pointer when it is desired to remove the disk from the shaft for purposes of repairing the mechanism.

From the above description it will be seen that a novel and extremely useful device has been provided to indicate the rate of .decrease in speed of rotation of a revolving element and that the device is particularly useful to determine the eiciency of the brakes in an automobile. The device may be used ,on either wheel and due to its novel coupling may be connected to the wheels of an automobile having hub caps of different diameters. Although a particular and preferred form of the .invention has been described modifications may be made and the invention is to be construed as broadly as the limitations in the claims, taken in conjunction with the ,prior art, may allow.

` Having thus described the invention, what is claimed as new and desired to besecured I by Letters Patent, is:

1. A device for measuring the rate of de crease in speed of rotation of al revolving element comprising a shaft, ing member` fast thereon, a weighted indicating member-mounted co-axially with the shaft, a one-Way clutch forrpositively driving the indicating member from the shaft, means interposing a yielding resistance to any movement` of the indicating member in advance of the shaft, and a coupling member for connecting the shaft to the revolving element, whereby when the revolving element is so connected and the speed of said revolving element is decreased the indicating member will have a forward rotation rela,- the extive to the indicia-carrying member,

by thel tent of which will be determined yielding resistance.

2. A device for measuring the rate of decrease in speed of rotation -of a revolving element comprising a' shaft, an indiciacarrying member fast thereon, a weighted indicating member mounted co-axially of the shaft, a one-way clutch for positively driving the indicating member. forwardly from the shaft, a spring yieldingly resisting forward turning movement of the indicating. member relative to the shaft, andv means foi" anV indicia-carrycoupling the shaft to the revolving element. whereby when the revolving element is connected to the shaft and the speed of 'said revolving element is decreased the indicating member will have a movement relative to the indicia-carrying member.

3. A device for measuring crease in speed of rotation of a revolving element comprising a shaft, an indicia-carrying member -rigid therewith, a weighted indicating member mounted co-axially of the shaft, a pawl and ratchet driving connection between the shaft and the indicating membera spring to resist yieldingly forward turning movement of the indicating member relative to the shaft, and a," coupling for connecting the shaft to the revolving element, whereby when the revolving element is connected to the shaft and the speed of said revolving element is decreased the the rate of deindicating meinber will have a movement relative to the indicia-carryinfr member.

' 4. A device for measuring'tlie rate of decrease in speed of rotation of a revolving element comprising a shaft, an indicia-carrying member fastv thereon, a weighted indicating member loosely mounted thereon,a pawl'and ratchet driving connection between said weighted indicating member and shaft, a spring connecting said indicating member to the shaft, and-arranged to'resist yieldingly forward movement of the indicating member relative to the shaft, and means for coupling said shaft to the revolving element, whereby when the speed of the revolving element is decreased the indicating member moves forwardly relative to the indiciacarrying member. Y' i 5. A device for measuring the rate of decrease in speed of rotation of a revolving element comprising a shaft, rying member fast thereon, a weighted indicating member loosely mounted on the shaft, means to drive the indicating member forwardly by the forward rotation of the shaft, said indicating member being permitted to turn forwardly relative to the shaft, a spring yieldingly resisting such relative forward movement, and means for coupling the shaft to the revolving element.

6. A brake tester for measuring theel.- ficiency of a brake in stoppingthe motion of a revolving element comprising a shaft.'

an indicia-carrying disk fast to the shaft. a ratchet fast to the 'shaft and to the disk. a weighted pointer loosely mounted on the shaft, a pawl carried by an indicia-cerf the pointer for engagement with the ratchet, a spring con" necting the pointer to the shaft, and a cou' veith Leeaevi ment by the engagement of the pawl with the ratchet thereby indicating the rate of decrease of the speed of the revolving element.

7. n automobile brake tester for measuring the efliciency of a brake in stopping the motion of a revolving wheel comprising a shaft, an indicia-carryingr disk fast to the shaft, two ratchets having opposed teeth fast and to the disk, a Weighted pointer loosely mounted on the shaft, two pawls carried by the pointer, means to place er pawl in engagement With its ratchet, means carried by the pointer to retain each paw] in engagement with the corresponding ratchet, a spring connecting the pointer to the shaft, and a coupling for connectimgT the shaft to the hub of the revolving Wheel, whereby when a Wheel revolving in either direction is connected to the shaft andthe whereby the coupling may be brakes applied to stop the motion of the t Wheel, the pointer due to its momentum moves past the disk and is retained at its farthest point of movement by ment of the appropriate pawl with the corresponding` ratchet therebyiindicating the rate of decrease of the speed of the Wheel and the efficiency of the brakee 8; A device such as described in claim in Which the couplingis a hollowT conical member secured to the shaft, with an interior conical facing ot' material-to frictionally engage the end of the rotating element,

appliedto rotating elements of various sizes.

ln testimony whereof, We have signed our names to this specification.

JOHN J. GRABFELD. FREDERICK A. KINCH, JR.,

tliengage? 

